1. Department of Electrical and Computer Engineering, Princeton University, Princeton, New Jersey 08544, United States
2. Holcombe Department of Electrical and Computer Engineering, Clemson University, Clemson, South Carolina 29634, United States
3. Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
4. School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
5. Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80303, United States
6. Department of Chemical and Biological Engineering, Department of Chemistry, and Materials Science and Engineering Program, University of Colorado Boulder, Boulder, Colorado 80303, United States
7. Materials Science Program, Colorado School of Mines, Golden, Colorado 80401, United States
8. National Renewable Energy Laboratory, Golden, Colorado 80401, United States
9. Andlinger Center for Energy and the Environment, Princeton University, Princeton, New Jersey 08544, United States